Research ideas for my Neurobiology class -- All Input Wanted Please

[Nick tringali]

TL;DR Summary

If you have any knowledge of neuroscience, drop me off some ideas to think about.

For my neurobiology class, my partners and I are expected to design an experiment of anything we would like to do.
Here is what we have thus far:
In class (Lab) we did a neuron culture by taking the forebrain from a chick egg. We did some processes and our objective was to culture it. Forgive me if I miss information, it was a tough lab and we did it weeks ago. Anyways, we did a polylysine treatment and a laminin treatment. The object was to see if there was a difference in dendritic growth.

We want to do something like that but use different chemicals. Does anyone have any chemicals in mind that would be interesting to use? Anything goes, so if you have any substance in mind, please respond. My group and I think that it would make for a better experiment if we can make increase axonal or dendritic growth rather than decreasing it. Does anyone have other cool approaches to increase growth other than adding chemicals? I am just brainstorming. Any help would be appreciated. This is a high level undergraduate class so I'm really trying to do something truly fascinating here. Can I mess with the genes of the chick egg?

 

[atyy]

Might electrical stimulation be worth investigating?
https://pubmed.ncbi.nlm.nih.gov/16511874/ (I haven't read it, just found it by googling)

 

[Nick tringali]

Might electrical stimulation be worth investigating?
https://pubmed.ncbi.nlm.nih.gov/16511874/ (I haven't read it, just found it by googling)

Absolutely, Thank you.

 

[BillTre]

Try comparing neurons from different sources.
The forebrain has a diversity of different neuron types. Each different type may respond differently.
The developmental time of the cultured cells could also have an effect.

You may be able to isolate a more refine source or cells, perhaps a periferal ganglia, like the Trigeminal ganglion (one of the largest, but probably has several kinds of cells) or a Dorsal Root Ganglion or maybe the Otic (ear) ganglion. Alternatively the spinal cord would probably have fewer different kinds of cells.

If you could apply your substrates in gradients, you could see which direction your fibers grow, or you could make concentration steps, maybe by coating half a dish, and then a less dense coating on the whole dish.

Possible substrates would be anything a wondering growth cone might encounter. These might include collogen and fibronectin. There are probably also a lot of commercially available substrates for growing neurons on in culture.
All this will require/be limited by some kind of budget.

You could also consider what is in your culture medium. Supplements are often added to cultures which can provoke different response.

Here is a google search I did that may have some interesting hits.

 

[jim mcnamara]

@BillTre - define supplements? -- in the context of your suggestion, please.

 

[BillTre]

Well, when I was culturing hybridomas, for example, I used some vitamin supplements, an endothelial cells growth factor, fetal calf serum. These probably bind cell surface receptors and may change cell behaviors.

Some supplements may bind to substrate molecules (perhaps to laminin, which is a major component of basal lamina), providing another substrate component for the cells interact with.

With respect to supplements specific to neurons, I am not very current on this.
However, in development growing neurons can get cues from a variety of different cells and tissues. Some of these have been traced to interactions with specific molecules and found to be effected by mutations in research animals like zebrafish, Drosophila, and C. elegans.
There are a lot of potential pathfinding cue molecules, which unfortunately, I am not current on.
Here is wikiipedia list from here:

A combination of genetic and biochemical methods (see below) has led to the discovery of several important classes of axon guidance molecules and their receptors:[2]

• Netrins: Netrins are secreted molecules that can act to attract or repel axons by binding to their receptors, DCC and UNC5.
• Slits: Secreted proteins that normally repel growth cones by engaging Robo (Roundabout) class receptors.
• Ephrins: Ephrins are cell surface molecules that activate Eph receptors on the surface of other cells. This interaction can be attractive or repulsive. In some cases, Ephrins can also act as receptors by transducing a signal into the expressing cell, while Ephs act as the ligands. Signaling into both the Ephrin- and Eph-bearing cells is called "bi-directional signaling."
• Semaphorins: The many types of Semaphorins are primarily axonal repellents, and activate complexes of cell-surface receptors called Plexins and Neuropilins.
• Cell adhesion molecules (CAMs): Integral membrane proteins mediating adhesion between growing axons and eliciting intracellular signalling within the growth cone. CAMs are the major class of proteins mediating correct axonal navigation of axons growing on axons (fasciculation). There are two CAM subgroups: IgSF-CAMs (belonging to the immunoglobulin superfamily) and Cadherins (Ca-dependent CAMs).

In addition, many other classes of extracellular molecules are used by growth cones to navigate properly:

• Developmental morphogens, such as BMPs, Wnts, Hedgehog, and FGFs
• Extracellular matrix and adhesion molecules such as laminin, tenascins, proteoglycans, N-CAM, and L1
• Growth factors like NGF
• Neurotransmitters and modulators like GABA

Some of these are cell surface molecules and may not work well just stuck down on a dish instead of on a cell surface.
However, I do think that several of the CAM's (Cell Adhesion Molecules) work that way.

 

[Tom.G]

Restoring neuron connections
"A synthetic peptide promotes functional recovery in neurodegeneration and spinal cord models"
P. C. Salinas Department of Cell and Developmental Biology, University College London, London, UK. p.salinas@ucl.ac.uk.

Injection of CPTX into the brains of mice deficient in synaptic connectivity restore glutamatergic synaptic connections and circuit function, which improved cognitive function. CPTX also repairs damaged neuronal circuits after spinal cord injuryin mice, which improved motor function.

Science magazine 28 August 2020, vol 369 issue 6507 pg 1502
doi.10.1126/science.abd4762

Cheers,
Tom